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Fighting Disease Through Wastewater Monitoring in World’s Largest Refugee Settlement

In the world’s largest refugee community, open sewage that runs between homes in shallow trenches overflows with frequent flooding. Children, many barefoot, play in fields at the bottom of hills, where wastewater runoff often settles. Nearly everyone baths in surface water, which is vulnerable to biological and chemical contamination. And the community cleans its open drains without protective gear.

Yet little is known about what types of pathogens are present in the Rohingya settlement of Cox’s Bazar, Bangladesh.

That’s about to change.

Bringing wastewater monitoring to this complex environment has the potential for enormous payoffs that will provide critical information on disease burden and location that can guide targeted community health interventions, offer a model for carrying out non-traditional disease surveillance efforts in other humanitarian settings, and simultaneously contribute to efforts to prevent or mitigate future pandemics.

These are the goals of icddr,b, a renowned public health research institution in Dhaka, Bangladesh, with over 60 years of experience measuring health outcomes and conducting research on public health interventions. The work is supported by The Rockefeller Foundation’s Pandemic Prevention Institute. Advice on sampling strategy, laboratory methods and analyzing and visualizing the data is provided by Emory University’s Center for Global Safe Water, Sanitation, and Hygiene.

“Current research and implementation of wastewater monitoring has predominately focused on wastewater treatment plants. The reality is, more communities around the world use other sanitation systems, like open sewage drains,” says Megan Diamonda Health Initiative Manager and wastewater surveillance lead at The Rockefeller Foundation. “Using this tool to detect harmful pathogens in the water could have tremendous public health benefits with applications that extend well beyond Cox’s Bazar.”

In the short-term, the monitoring also has the potential to provide disease information on the larger population, as the porous border between the Rohingya settlement and host community of Cox’s Bazar is pierced by rivers and canals that contain human excreta.

“If we fail to protect the health of the Rohingyas, the health of the locals will also be at risk because the pathogens are circulating through wastewater, water, food and personal contact,” noted Dr. Nuhu Amin of icddr,b, who works directly with the Rohingya community and is also a doctoral student focusing on wastewater research and safe sanitation approaches at the Institute for Sustainable Futures at the University of Technology Sydney, Australia.

“The Rohingya refugees are one of the most vulnerable populations in the world,” explained Dr. Christine Moe, Director of the Center for Global Safe Water, Sanitation, and Hygiene at Emory University. “Monitoring wastewater will provide a better understanding of the true disease burden in this population and will allow health authorities to focus vaccination campaigns and other interventions more effectively to protect the health of the Rohingya and neighboring communities.”

With Open Sewage, Waterborne Diseases Prevail

An estimated 900,000 stateless Rohingya live in Cox’s Bazar District on Bangladesh’s coast. Most arrived in August 2017, fleeing persecution and violence in Myanmar, some carrying children in their arms or meager belongings balanced on their heads.

The district headquarters of the same name is a fishing port and tourist spot famous for a 75-mile stretch of natural sand beach, the world’s longest. On this landscape, 34 refugee camps also converged that summer, giving Cox’s Bazar another record: home to the world’s largest refugee settlement. An additional 250,000 people live in the surrounding host communities and millions of tourists also visit annually.

The country lacks resources to adequately accommodate the displaced Rohingya population, who are not permitted legally to leave their congested camps. While it is hard to precisely know the Covid-19 infection rate due to limited access to clinical tests, enforced isolation may have contributed to a relatively low number of reported cases.

pipes from Rohingya homes dump wastewater into open drains
Pipes from Rohingya homes dump wastewater into open drains

It is clear, even without a robust disease surveillance system in place, that outbreaks of waterborne diseases prevail in the camp—including diarrhea, one of the leading causes of child mortality across the globe, and cholera, which can also kill within hours if left untreated.

person cleaning open wastewater drains.
Cleaning open wastewater drains

Patchwork Sanitation System Increases the Challenge

As an emergency response rather than a sustainable sanitation system, about 26,000 temporary emergency latrines have been installed in the settlement since the 2017 influx. The patchwork arrangement includes about 80 percent pit latrines, 10 percent septic tanks, and the remainder other on-sit sanitation systems.

Add to the mix natural disasters such as cyclones and heavy rain that causes regular flooding, and it is clear this is a complex environment for disease surveillance.

Wastewater monitoring, which doesn’t rely on data from a healthcare system or individual diagnostic testing, may prove to be an important contributor to helping public health authorities understand the current SARS CoV-2 infection rate, as well as identify other key infectious diseases circulating in the community.

The information provided by this surveillance will supplement scarce diagnostic testing, and can help guide decisions about where to prioritize limited resources, including vaccine campaigns and behavioral changes to fight Covid-19, cholera, typhoid, and rotavirus, all of which have been seen in Cox’s Bazar.

The proof-of-concept project funded by the Pandemic Prevention Institute focuses on standing up and evaluating wastewater monitoring in four to five camps. As a first step, the team will conduct an assessment of the local sanitation infrastructure to understand where fecal waste accumulates and flows, and use this to inform their sampling strategy. Wastewater samples will be tested for SARS-CoV-2, Salmonella Typhi, Vibrio cholerae, and Human rotavirus. A subset of the samples that contain SARS-CoV-2 will be analyzed for genomic variants circulating among Rohingya community.

The team will initially transport all wastewater samples to the icddr,b laboratory in Dhaka for analysis, but may eventually work toward analyzing directly in the field.

Dr. Nuhu Amin: A Crucial Resource

Within the refugee community, this work will be coordinated through local block leaders known as majhis who serve as mediators between the Rohingya population and the Bangladeshi government or humanitarian workers.

This is one reason why Dr. Amin is key to the project’s success. A Bangladesh native, he has more than 12 years of experience managing and implementing research projects in Bangladesh and has worked with the Rohingya population for the last five years. This has made him a trusted messenger within the community.

people cleaning open sewage drain
Rohingya community works to clean open sewage drains (All photos courtesy of Dr. Nuhu Amin)

“I work closely with the majhis, and each majhi is influential to about 100 or so households. So if they are convinced, the way is cleared,” says Dr. Amin.

The community was cautious at first, though, and did not even want to accept treated drinking water from officials. Given historical state-based violence, they feared the water would be unsafe, Dr. Amin said. “It was very challenging in the beginning,” he said. “It took more than a year to build this bridge.”

But it was time well-spent, he says.

“We believe the wastewater surveillance at Cox’s Bazar should be able to generate evidence for the causes of viral and diarrheal diseases. We should also be able to spot signs of an outbreak—SARS CoV-2 or cholera or something else. And this will help determine where to apply therapeutics—or even where to encourage even simple behavioral changes.”

wastewater sewage.
Wastewater sludge behind Rohingya homes

An Important Component of Global Early Warning System

The Pandemic Prevention Institute envisions braiding traditional and nontraditional monitoring – including genomic sequencing as well as environmental, mobility and consumer data –to create the signals needed for a global early warning system to trigger action that protects lives and stops the spread of harmful pathogens.

To help achieve this mission, the Institute is a leading voice in highlighting how wastewater monitoring is a vital tool for early pathogen detection, especially in places with limited disease surveillance infrastructure.

In addition to Bangladesh, the Institute has supported multiple wastewater surveillance programs in low-and-middle-income countries, including Ghana, India and Malawi. Together with grantees in the United States, they are refining protocols for wastewater sampling and testing, developing metrics to inform risks thresholds, and exploring novel approaches for sampling in non-sewered environments.

More recently, the Institute brought together over 150 wastewater surveillance experts representing more than 40 countries, including 25 percent from low-and-medium-income countries. The goal of the gathering, organized in collaboration with the UK Health Security Agency, was to create a forum for future evidence generation and cross-country collaboration.

“There is a clear desire and need for leadership and investment in wastewater surveillance as an efficient means to keep people safe from existing and novel pathogens,” Diamond said. “The work at Cox’s Bazar represents an important step forward in creating a disease containment strategy that is designed to operate within the context of a vulnerable community.”